Navigation apparatus

ABSTRACT

Map data stored in a memory includes normal road data and additional road data for predetermined regions along a highway. A current location of a moving body is detected by sensor(s). The normal road data or additional road data is selected on the basis of the detected current location of the moving body. A map matching process is performed with the selected road data. Accordingly, the current location of the moving body is determined in the map matching process with high accuracy.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a navigation apparatus for detecting acurrent location of a mobile body.

2. Description of the Related Art

One type of known car navigation apparatus uses a recording medium suchas CD-ROM which has map data stored therein. The map data includes roaddata which represent locations (or points) along streets/roads on a mapby numbers. The car navigation apparatus detects a current location ofthe car and a moving direction of the car by using various sensors whenthe car is operated (or moving). At the same time, the car navigationapparatus reads a group of map data covering a certain area, whichincludes the current location of the car, from the recording medium toshow a map of the area around the car in a display unit. The currentlocation and moving direction of the car are both indicatedautomatically in the displayed map.

In the past, the navigation apparatus relies upon two navigationschemes. One scheme is self-contained navigation and the other scheme isGPS (global positioning system) navigation. The self-containednavigation utilizes self-contained sensors (e.g., acceleration sensorand angular velocity sensor) integrated in the navigation apparatus anddoes not receive any external support or information. The accelerationsensor and angular velocity sensor are used to detect (measure)navigation parameters such as acceleration and angular velocity of thecar. The GPS navigation utilizes a plurality of artificial satelliteswhich send measurement data (position data) to the navigation apparatus.The self-contained navigation has advantages and disadvantages, and theGPS navigation has advantages and disadvantages. In recent times,therefore, hybrid navigation is generally used, which combines(compares) measurement data supplied from the self-contained navigationwith measurement data supplied from the GPS navigation.

In order to improve detection accuracy of a current car locationprovided by the self-contained navigation or GPS navigation, a mapmatching technique is also employed. The map matching technique orprocess causes the detected car location to shift to the road of the mapdata (road corresponding to the map data) while the car is moving, ifthe detected car location deviates from the road of the map data. Oneexample of such map matching process is disclosed in Japanese PatentKokai No. 10-307037.

In the map matching process disclosed in Japanese Patent Kokai No.10-307037, map data is used, which is stored beforehand in a storagedevice. The map data indicates a location of the car on a road for mapmatching. The map data includes a region, in which a current carlocation obtained by the self-contained navigation or GPS navigation ispresent, and read from the storage device. Then, the car location on theroad of the map data, read from the storage device, is compared with thecar location obtained by the self-contained or GPS navigation. However,the car location on the road indicated in the map data is sometimesinappropriate for a driver of the car since an actual location of thecar on the real road is very different from the car location presentedby the map data when the car is moving under certain running conditionsand/or in a certain area of the road (e.g., it depends which floor of afive-story parking garage (tower) the car is heading for or which laneof a three-lane highway the car is taking). In addition, map data itselfis often not available in the storage unit for a particular location orregion on the earth. As a result, the current location of the car cannotalways be determined with high accuracy. This problem is also true toother types of navigation apparatus designed for other mobile bodies,such as a human.

SUMMARY OF THE INVENTION

An object of the present invention is to provide a navigation apparatusthat can determine a current location of a moving body with highaccuracy by a map matching process.

According to one aspect of the present invention, there is provided anavigation apparatus comprising: a current position detector forproducing data about a current location of a mobile body on the basis ofat least one of navigation parameters of the mobile body and measurementdata supplied from a plurality of artificial satellites; a storagedevice for storing map data which includes road data representing oneroute on a road, the map data also including additional road data for apredetermined region on the road, the additional road data representinganother route on the road other than the one route; and a map matchingdevice for applying a map matching process to the data produced by thecurrent position detector, using the road data, to determine the currentlocation of the mobile body when the mobile body is not adjacent to thepredetermined region, and for applying the map matching process to thedata produced by the current position detector, using either theadditional road data or the road data depending upon a moving conditionof the mobile body, to determine the current location of the mobile bodywhen the mobile body is adjacent to or in the predetermined region. Itis therefore possible to determine the current location of the mobilebody by the map matching process with high accuracy.

According to another aspect of the present invention, there is provideda navigation apparatus for determining a current location of a mobilebody which moves in a multi-story building, comprising: a currentposition detector for producing data about the current location of themobile body on the basis of at least one of navigation parameters of themobile body and measurement data supplied from a plurality of artificialsatellites; a story detector for detecting a story of the multi-storybuilding in which the mobile body is present; a storage device forstoring map data which includes a plurality of road data representing aplurality of stories of the multi-story building respectively; and a mapmatching device for retrieving road data representing the story detectedby the story detector from the storage device, and applying a mapmatching process to the data produced by the current position detector,using the retrieved road data, to determine the current location of themobile body.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a block diagram of a navigation apparatus mounted ina car;

FIG. 2 illustrates a flowchart of a car location indicating processperformed by a control circuit of the navigation apparatus shown in FIG.1;

FIG. 3 illustrates a flowchart of a road data selecting processperformed by the control circuit of the navigation apparatus shown inFIG. 1;

FIG. 4 illustrates a flowchart of a floor-to-floor movementdetermination process performed by the control circuit of the navigationapparatus shown in FIG. 1;

FIG. 5 illustrates normal road data and additional road data for amulti-lane highway;

FIG. 6 illustrates a table showing relationship between the normal roaddata and additional road data;

FIG. 7 illustrates a map data table for respective floors of amulti-floor car park;

FIG. 8A illustrates a map derived from the map data of the secondbasement of the multi-floor car park;

FIG. 8B illustrates a map derived from the map data of the thirdbasement of the multi-floor car park; and

FIG. 9 illustrates a slope between two floors in the multi-floor carpark, and a timing when a floor to floor movement is determined.

DETAILED DESCRIPTION OF THE INVENTION

Embodiments of the present invention will be described in reference tothe accompanying drawings.

Referring to FIG. 1, a car navigation apparatus according to oneembodiment of the present invention is schematically illustrated. Thecar navigation apparatus is located in a car (not shown). Theillustrated car navigation apparatus includes a GPS device 1, speedsensor 2, angular velocity sensor 3, acceleration sensor 4, map datastorage device 5, operation unit 6, display unit 7 and control circuit8. The GPS device 1 is connected to a GPS antenna 1 a to receive radiowaves (signals) transmitted from a plurality of artificial satellites(not shown) thereby calculating and determining GPS car location dataincluding a current location of the car and a moving direction of thecar on the basis of the radio waves. The speed sensor 2, angularvelocity sensor 3 and acceleration sensor 4 are self-contained sensorsto detect (determine) the current location and moving direction of thecar without using information from outside. The speed sensor 2 detects aspeed of the car. The angular velocity sensor 3 detects an angularvelocity of the car. The acceleration sensor 4 detects acceleration ofthe car.

The map data storage unit 5 includes a recording medium such as DVD anda drive device for the recording medium. Information (data) such as mapdata is recorded in the recording medium beforehand. The map datastorage unit 5 reads (retrieves) the map data and other information fromthe recording medium. The map data includes road data which represents aparticular route, lane or line on an actual road. The map data alsoincludes data about parking lots, multi-story garages (towers) and tollgates. The data about the parking lots may include confines of eachparking lot, driveways in each parking lot and respective parking areasin each parking lot. The operation unit 6 is operated by a user to enterdata and instructions into the navigation apparatus. The display unit 7displays navigation (cruising) information such as a map.

The control circuit 8 is, for example, a micro computer. The controlcircuit 8 is connected to the GPS device 1, speed sensor 2, angularvelocity sensor 3, acceleration sensor 4, map data storage unit 5,operation unit 6 and display unit 7 to control the navigation apparatus.

The control circuit 8 receives output data of the GPS device 1, speedsensor 2, angular velocity sensor 3 and acceleration sensor 4periodically to determine the current location and moving direction ofthe car at predetermined intervals. The control circuit 8 then causesthe display unit 7 to show a map around the current location of the cartogether with a car mark (car location mark). The car mark is placed atthe current location of the car in the displayed map, and shows themoving direction of the car. The process for indicating the car mark inthe displayed map is referred to as a car position indicating process.The car position indicating process will be described in reference toFIGS. 1 and 2.

As shown in the flowchart of FIG. 2, the control circuit 8 determineswhether a flag F is “1” or not (Step S1). The flag F is set to be “1”when the car is in a parking lot or tower at Step S7 (will bedescribed). If the current location of the car is outside the parkinglot or tower and the GPS device 1 can accurately determine the currentlocation of the car, the flag F is set to “0” at Step S13 (will bedescribed). An initial value of the flag F is “0”.

When it is determined at Step S1 that F is “0”, the control circuit 8obtains GPS car position data from the GPS device 1 (Step S2). Thecontrol circuit 8 also obtains car position data from the self-containedsensors (Step S3). The car position data supplied from theself-contained sensors is referred to as self-contained car positiondata. Before the car position indicating process starts (or aside fromthe car position indicating process), the control circuit 8 periodicallycalculates self-contained car position data from speed, angular velocityand acceleration of the car, which are obtained from output data of thespeed sensor 2, angular velocity sensor 3 and acceleration sensor 4 atprescribed intervals, and stores the self-contained car position data ina separate memory (not shown). The self-contained car position datastored in the separate memory includes the current location and movingdirection of the car. The self-contained car position data is read fromthe separate memory at Step S3.

After Step S3, the control circuit 8 determines corrected car positiondata from the GPS car position data and self-contained car position data(Step S4). The control circuit 8 then performs map matching process onthe corrected car position data with respect to the road derived fromthe map data (Step S5). At Step S4, the GPS car position data iscombined to the self-contained car position data to obtain the correctedcar position data. The corrected car position data includes a correctedcurrent location of the car and a corrected moving direction of the car.A method of combining the GPS car position data with the self-containedcar position data is described in detail in, for example, JapanesePatent Kokai Nos. 9-297030 and 10-30736, entire disclosures of which areincorporated herein by reference. At Step S5, the map data around thecurrent car location is read from the map data storage device 5. If thecurrent car location indicated by the corrected car position data is notpresent on the road of the map data, the current car location of thecorrected car position data is forced to shift on the road of the mapdata. If, on the other hand, the current car location of the correctedcar position data is present on the road of the map data, the currentcar location given by the corrected car location data is maintained.

Subsequently, the control circuit 8 determines whether the current carlocation determined at Step S5 is within confines of a parking lot, onthe basis of the map data retrieved from the storage device 5 (Step S6).If the current car location is within the confines of the parking lot,the flag F becomes “1” (Step S7). The control program then proceeds toStep S9.

If the current car location is outside the parking lot (No at Step S6),the control circuit 8 causes the display unit 7 to show a map includingthe current car location determined at Step S5, together with an arrow(car mark) (Step S8). A location of the arrow in the display screenindicates the current location of the car. The arrow also indicates theheading direction of the car.

If it is determined that F is “1” at Step S1, it means that the car iswithin the parking lot or that the car is outside the parking lot butthe current location of the car cannot be accurately detected by the GPSdevice 1. When F=1, therefore, the control circuit 8 obtains carposition data from the self-contained sensors (Step S9). Step S9 is thesame as Step S3.

After Step S9, the control circuit 8 performs the map matching processon the current car location obtained by the self-contained sensors withrespect to the road derived from the map data (Step S10). At Step S10,the map data around the current car location is read from the map datastorage device 5. If the current car location indicated by theself-contained navigation is not present on the road of the map data,the current car location of the self-contained navigation is forced toshift on the road of the map data. If, on the other hand, the currentcar location of the self-contained navigation is present on the road ofthe map data, the current car location given by the self-containednavigation is maintained.

Subsequently, the control circuit 8 determines whether the current carlocation determined at Step S10 is outside the parking lot, on the basisof the map data retrieved from the storage device 5 (Step S11). If thecurrent car location is outside the parking lot, it is determinedwhether the car has moved a predetermined period or distance outside theparking lot (Step S12). If the answer is yes, the flag F becomes “0”(Step S13). The control program then return to Step S2.

If the current car location is within the parking lot (No at Step S11)or if the car has not moved the predetermined period or distance afterleaving the parking lot (No at Step S12), the program proceeds to StepS8. The control circuit 8 then causes the display unit 7 to show a mapincluding the current car location determined at Step S10, together withthe car mark arrow.

In the above described car position indicating process, the current carlocation is determined from the GPS car position data obtained from theGPS device 1, the self-contained car position data obtained from theself-contained sensors (i.e., speed sensor 2, angular velocity sensor 3and acceleration sensor 4) and the map matching process when the car iscruising under a normal condition (prior to entering the parking lot).On the other hand, when the car enters the parking lot and moves in theparking lot, the current car location is determined from theself-contained car position data obtained from the self-containedsensors and the map matching process. The GPS car position data from theGPS device 1 is disregarded. When the car is cruising in the parkinglot, more accurate current location of the car can be obtained by simplyapplying the map matching process to the self-contained car positiondata, rather than by applying the map matching process to thecombination of the GPS car position data and self-contained car positiondata. Even if the car exits the parking lot, the GPS car position datais still inaccurate till the predetermined period or distance isreached. Thus, the current car location is determined by applying themap matching process to only the self-contained car position data.

The road of the map data (road data) used in the map matching process isselected by a road data selection process (FIG. 3) which is repeatedlyexecuted by the control circuit 8.

In the road data selection process shown in FIG. 3, the control circuit8 reads map data of a region including the current car location from themap data storage device 5 (Step S21). The current car location in theflowchart of FIG. 3 may be a current car location which is most recentlydetermined by the car location indicating process. Alternatively, thecurrent car location in FIG. 3 may be the most recent current carlocation determined by the GPS device or self-contained sensors.

The control circuit 8 determines whether the map data has additionalroad data for the current car location (Step S22). The map data hasnormal (representative, standard) road data and additional road data fora certain region on the road even if the current car location is presenton the road of the map data. For example, if the car is cruising on athree-lane highway (one lane for right turn, one lane for straight andone lane for left turn), the normal road data may represent the straight(center) lane and the additional road data may represent the right andleft turn lanes (side lanes).

If there is no additional road data for the current car location on theroad of the map data, the normal road data of the map data is selected(Step S23). If, on the other hand, the additional road data exists, thecontrol circuit 8 determines whether the car has made a turn (Step S24).A fact that the car has turned to the right or left is known from themost recent moving direction of the car, which is obtained from the mostrecent GPS car position data or self-contained car position data. If thecar is moving straight, the program proceeds to Step S23 to use thenormal road data of the map data. If the car turns, the additional roaddata is used rather than the normal road data (Step S25).

After Step S23 or S25, the control circuit 8 determines whether thecurrent car location is in a parking tower (Step S26). Step S26 issimilar to Step S6, but a contour polygon which defines confines of theparking tower (will be described) is utilized to make a determination atStep S26. If the current car location is within the parking tower, thecontrol circuit 8 determines whether the car has moved to another floorin the tower (Step S27). The floors of the tower may have differentfeatures (designs, arrangements) so that different map data may beprepared for the respective floors. Step S27 is therefore necessary toknow whether the car has moved to another floor. A method of determiningwhether the car has moved to another floor will be described in detaillater (FIG. 4). If it is determined that the car is now on a differentfloor, road data for the current floor is utilized (Step S28). If it isdetermined at Step S26 that the car is outside the parking tower, or atStep S27 that the car remains on the same floor, the normal road dataselected at Step S23 is continuously utilized.

Referring to FIG. 4, the determination process for the floor-to-floormovement at Step S27 will be described.

The control circuit 8 first determines whether an inclination flag F1 is“1” (Step S31). The slope (inclination) flag F1 is set to be “1 ” atStep S34, and an initial value of the slope flag F1 is “0”. If the slopeflag F1 is “0”, the control circuit 8 determines whether slope data isavailable at the current car location (Step S32). The map data read fromthe storage device 5 includes the slope data when the current carlocation is in the vicinity of a branching point of the road and one ofthe enterable branching roads is a slope. The slope data includes aninclination angle of the slope. Thus, when the slope data is obtainedfrom the map data for the current car location, it means that at leastone of the branching roads has an inclination and the car can enter theinclined road.

When no slope data is available in the map data storage device 5 for thecurrent car location, the flag F1 is set to be “0” (Step S33).Contrarily, when the slope data is obtained from the storage device 5for the current car location, the flag F1 is set to be “1” (Step S34).The control circuit 8 then causes a running distance meter or calculator(not shown) to start counting the running distance of the car (StepS35). At Step S35, the running distance meter is initialized (to zero)to count the traveling distance of the car after the slope data isobtained. The running distance meter calculates the running distance onthe basis of a car speed derived from the speed sensor 2 and a timederived from a clock. The running distance meter (calculator) may behardware or software.

After Step S35, the control circuit 8 determines whether the runningdistance calculated by the running distance meter reaches a referencedistance D (Step S36). If the car has run the reference distance D ormore, the control circuit 8 then determines whether a difference betweenan actual inclination angle of the road at the current car location andthe inclination angle of the slope data is equal to or smaller than apredetermined angle A1 (Step S37). The actual inclination angle of theroad at the current car location is calculated in the control circuit 8on the basis of acceleration of the car which is detected by theacceleration sensor 4. The inclination angle calculating process may beexecuted at the same time as Step S37 or independently.

The method of calculating the actual inclination angle is disclosed in,for example, Japanese Patent Kokai No. 10-253352, the entire disclosureof which is incorporated herein by reference, and will be describedbriefly below.

First, acceleration Gc applied to the car in the car moving direction isdetected by the acceleration sensor 4. A traveling distance of the caris obtained on the basis of an output signal of the speed sensor 2, anddifferentiated twice to calculate acceleration Gb of the moving car.Then, the acceleration vector Gb is subtracted from the accelerationvector Gc to calculate a component Ga of the acceleration of gravity Gin the car moving direction. Thus, Ga=Gc−Gb. The calculated accelerationGa and acceleration of gravity G are used to calculate the actualinclination angle θ from the equation (1).θ=sin⁻¹(|Ga|/|G|)  (1)

When the difference between the actual inclination angle and theinclination angle of the slope data is greater than the predeterminedangle A1, the running distance meter is activated again to measure thereference distance D from the beginning (Step S38). On the other hand,when the difference between the actual inclination angle and theinclination angle of the slope data is not greater than thepredetermined angle A1, the control circuit 8 stops the measurement ofthe running distance with the running distance meter (Step S39) and theflag F1 is set to be “0” (Step S40). In this case, the control circuit 8considers that the car is moving from the current floor to a next floor.As a result, the control program proceeds to Step S28 (FIG. 3) to switchto the map data of the next floor from the map data of the current floorfor the current car location. Road data is then selected form the mapdata of the next floor. In other words, when Step S28 is executed, themap data used for the map matching at Step S5 or S10 (car locationindicating process) is changed.

When Step S36 determines that the running distance has not reached thereference distance D or when the measuring of the running distance isrestarted at Step S38, the control circuit 8 determines whether theactual inclination angle is equal to or greater than the referenceinclination angle A (Step S41). If the actual inclination angle is notless than the reference inclination angle A, the control programproceeds to Step S28, and the control circuit 8 considers that the caris moving from the current floor to the next floor. As a result, the mapdata of the current floor is changed to the map data of the next floorfor the current car location. The road data is then selected form themap data of the next floor.

As shown in FIG. 5, an entrance/exit of the parking lot or tower mayface a highway which has a plurality of lanes (not shown). In the roaddata selection process, additional road data is available for a rightturning lane (route), in addition to normal road data for a straightcenter lane (route) (or a center line) of the highway. FIG. 6illustrates the normal road data and additional road data included inthe map data read from the storage device 5. In FIG. 6, DA0 to DAnrepresent coordinates of various points along the center line of thehighway to define the normal road data, and DA′2 to DA′6 representcoordinates of various points along the side lane to define theadditional road data. The side lane coordinates DA′2 to DA′6 correspondto the center lane (center line) coordinates DA2 to DA6.

When the driver of the car intends to enter the parking lot, the carusually runs in the side lane and turns to the right as indicated by thebroken line in FIG. 5. Therefore, if the map matching process isperformed with the normal road data, certain discrepancy (deviation,error) arises between the actual running distance of the car and therunning distance expected (predicted, assumed, calculated) on the basisof the map data after turning to the right. On the other hand, if themap matching process is performed with the additional road data, thediscrepancy between the actual running distance and the expected runningdistance until the parking lot entrance after the turning is reduced. Ofcourse, the reduced discrepancy less affects the expected runningdistance of the car after entering the parking lot. When the car exitsthe parking lot and enters the highway, the additional road data isutilized again in the map matching process to reduce the discrepancybetween the actual running distance and the expected running distanceafter exiting the parking lot.

If the car moves in a multi-story car park, the map data which includesroad data for respective stories as shown in FIG. 7 is used. A story inwhich the car is currently running is detected, and the map data for thecurrent story is utilized in the map matching process. Each story mayhave different arrangement or structure. For instance, as illustrated inFIGS. 8A and 8B, the parking space arrangement on the second basementmay be different from that on the third basement. It should be assumedhere that the car is moving from the second basement to the thirdbasement through a connecting slope. The map data of the second basementis switched to the map data of the third basement in this embodiment atan appropriate timing. The map data of the second basement is keptdisplayed till the car reaches a quarter of the circle of the connectingslope. If the map data of the second basement (FIG. 8A) is immediatelyswitched to that of the third basement (FIG. 8B) upon entering theconnecting slope, a car driver may think that the car is moving throughthe wall.

Referring to FIG. 9, the connecting slope between the two stories isschematically illustrated. The connecting slope is generally short andsteep. The maximum inclination of the connecting slope is, for example,six to nine degrees. Step S37 of FIG. 4 is executed when the car hasmoved the reference distance D from the start point T1. Specifically, itis determined that the difference between the actual inclination angleand the inclination angle of the slope data is not greater than thepredetermined angle A1 when the car has run the distance D. Theinclination angle of the slope data is obtained at the time T1. Thus, ifthe driveway on the currently running story extends next to theconnecting slope directed to the upper story and the car is moving tothe connecting slope, the map matching process is promptly performedwith the road data of the upper story after Steps S37, S39 and S40.

As described above, Step S26 in FIG. 3 determines whether the carcurrently exists in the parking lot or tower. This determinationprevents the map matching process from being disabled when the car exitsthe parking lot or tower. For some reasons, the currently running storyin the multi-story parking tower might be incorrectly detected and thecurrent car location and/or moving direction might be incorrectlydetected. When such incorrect detection occurred when the car moved inthe parking lot/tower, the map matching to the highway outside theparking lot/tower would become impossible when the car exits the parkinglot/tower. In order to prevent this, data about the confines of theparking lot or tower is stored in the storage device 5 as contour(boundary) polygon data, and Step S26 determines whether the car isoutside or inside the contour polygon, when the map matching to thedriveway in the parking lot/tower becomes impossible. The map matchingto the highway is initiated when Step S26 determines that the car isoutside the parking lot/tower.

Although not illustrated, the map data may also include road data forall lanes at a toll gate. For instance, a three-lane highway may spreadto ten lanes at a toll gate. The display unit 7 may show an appropriatemap by determining which lane the car takes.

It should be noted that the present invention is not limited to theillustrated and described embodiments. For example, the mobile body isthe car in the embodiments, but the mobile body may be a human. Theparking lot/tower may be replaced with a department store or restaurantif the mobile body is a human.

Although the self-contained sensors are the speed sensor 2, angularvelocity sensor 3 and acceleration sensor 4 in the above describedembodiments, a geomagnetic sensor and/or other sensors may be employed.

This application is based on Japanese patent application No.2001-137206, and the entire disclosure thereof is incorporated herein byreference.

1. A navigation apparatus comprising: a current position detector forproducing data of a current location of a mobile body on the basis of atleast one of navigation parameters of the mobile body and measurementdata supplied from a plurality of artificial satellites; a storagedevice for storing map data which includes road data representing oneroute on a road, the map data also including additional road data for apredetermined region on the road, the additional road data representinganother route on the road other than the one route; and a map matchingdevice for applying a map matching process to the data produced by thecurrent position detector, using the road data, to determine the currentlocation of the mobile body when the mobile body is not adjacent to thepredetermined region, and for applying the map matching process to thedata produced by the current position detector, using one of theadditional road data and the road data depending upon a moving conditionof the mobile body, to determine the current location of the mobile bodywhen the mobile body is adjacent to or in the predetermined region. 2.The navigation apparatus according to claim 1, wherein the map matchingdevice includes a moving condition detector for determining whether aturning movement of the mobile body occurs adjacent to the predeterminedregion, the turning movement being the moving condition of the mobilebody, and the map matching device applies the map matching process usingthe additional road data to determine the current location of the mobilebody when the turning movement of the mobile body is detected by themoving condition detector.
 3. The navigation apparatus according toclaim 1, wherein the mobile body is at least one of a car and a human.4. The navigation apparatus according to claim 1 further including aspeed sensor, an angular velocity sensor and an acceleration sensor toprovide the navigation parameters of the mobile body.
 5. The navigationapparatus according to claim 1, wherein the measurement data suppliedfrom the plurality of artificial satellites is GPS data.
 6. Thenavigation apparatus according to claim 1, wherein the current positiondetector compares the navigation parameters of the mobile body with themeasurement data supplied from the plurality of artificial satellites toproduce the data of the current location of the mobile body.
 7. Thenavigation apparatus according to claim 1 further including adetermination unit to determine whether the mobile body exists withinconfines of a predetermined structure.
 8. The navigation apparatusaccording to claim 7, wherein the current position detector only usesthe navigation parameters of the mobile body to produce the data of thecurrent location of the mobile body when the determination unitdetermines that the mobile body exists in the confines of thepredetermined structure.
 9. The navigation apparatus according to claim1, wherein the road is a multi-lane highway, the road data represents acenter lane of the multi-lane highway and the additional road datarepresents a side lane of the multi-lane highway.
 10. A navigationapparatus for determining a current location of a mobile body whichmoves in a multi-story building, comprising: a current position detectorfor producing data of the current location of the mobile body on thebasis of at least one of navigation parameters of the mobile body andmeasurement data supplied from a plurality of artificial satellites; astory detector for detecting a story of the multi-story building inwhich the mobile body is present; a storage device for storing map datawhich includes a plurality of road data representing a plurality ofstories of the multi-story building respectively; and a map matchingdevice for retrieving road data representing the story detected by thestory detector from the storage device, and applying a map matchingprocess to the data produced by the current position detector, using theretrieved road data, to determine the current location of the mobilebody.
 11. The navigation apparatus according to claim 10, wherein thestory detector detects the story in which the mobile body is present,when the current location of the mobile body detected by the currentposition detector is within the multi-story building.
 12. The navigationapparatus according to claim 10, wherein the mobile body is at least oneof a car and a human.
 13. The navigation apparatus according to claim 10further including a speed sensor, an angular velocity sensor and anacceleration sensor to provide the navigation parameters of the mobilebody.
 14. The navigation apparatus according to claim 10, wherein themeasurement data supplied from the plurality of artificial satellites isGPS data.
 15. The navigation apparatus according to claim 10, whereinthe story detector determines whether the mobile body is moving toanother story from a story in which the mobile body is currentlypresent.
 16. The navigation apparatus according to claim 15 furtherincluding a display unit for showing a map of the story in which themobile body is present.
 17. The navigation apparatus according to claim16, wherein the display unit shows a map of the another story when thestory detector determines that the mobile body is moving to the anotherstory.
 18. The navigation apparatus according to claim 10, wherein thecurrent position detector only uses the navigation parameters of themobile body to produce the data of the current location of the mobilebody when the current location of the mobile body detected by thecurrent position detector is within the multi-story building.
 19. Amethod of determining a current location of a mobile device, comprisingthe steps of: A) providing map data which includes road datarepresenting one route on a road, the map data also including additionalroad data for a predetermined region on the road, the additional roaddata representing another route on the road other than the one route; B)producing data of a current location of the mobile body on the basis ofat least one of information supplied from self-contained sensors andinformation supplied from a GPS device; and C) applying a map matchingprocess to the data produced in Step B, using the road data, todetermine the current location of the mobile body when the mobile bodyis not adjacent to the predetermined region, and for applying the mapmatching process to the data produced in Step B, using either one of theadditional road data and the road data depending upon a moving conditionof the mobile body, to determine the current location of the mobile bodywhen the mobile body is adjacent to the predetermined region.
 20. Amethod of determining a current location of a mobile body which moves ina multi-story building, comprising the steps of: A) providing map datawhich includes a plurality of road data representing a plurality ofstories of the multi-story building respectively; B) producing data ofthe current location of the mobile body on the basis of at least one ofinformation supplied from self-contained sensors and informationsupplied from a GPS device; C) detecting a story of the multi-storybuilding in which the mobile body is present; D) retrieving road datarepresenting the story detected in Step C from the map data; and E)applying a map matching process to the data produced in Step B, usingthe road data retrieved in Step C, to determine the current location ofthe mobile body.
 21. A navigation apparatus, comprising: a memory thatstores first road data representing a first route on a road and thatstores second road data representing a second route on the road; and acontroller that performs a map matching routine to determine a currentlocation of a mobile body, wherein the controller performs the mapmatching routine based on the first road data to determine the currentlocation when the mobile body is not in a predetermined region of theroad, wherein the controller performs the map matching routine based onthe second road data to determine the current location when the mobilebody is in the predetermined region.
 22. The navigation apparatusaccording to claim 21, wherein, when the mobile has a first movingcondition, the controller performs the map matching routine based on thesecond road data to determine the current location when the mobile bodyis in the predetermined region, and wherein, when the mobile has asecond moving condition, the controller performs the map matchingroutine based on the first road data to determine the current locationwhen the mobile body is in the predetermined region.
 23. A navigationapparatus, comprising: a detector for detecting a detected story of amulti-story building in which a mobile body is present; a memory thatstores first story data that represents a first story of the multi-storybuilding and that stores second story data that represents a secondstory of the multi-story building; and a controller that performs a mapmatching routine, wherein the controller determines a current locationof the mobile body based on the detected story detected by the detectorand based on at least one of the first story data and the second storydata.
 24. The navigation apparatus according to claim 21, wherein thecontroller determines whether the mobile body exists within confines ofa predetermined structure.
 25. The navigation apparatus according toclaim 24, wherein, when the predetermined structure comprises amulti-story building, the controller determines the current location ofthe mobile body by determining a story of multi-story building on whichthe mobile body is located.
 26. The navigation apparatus according toclaim 21, wherein the road is a multi-lane road, the first road datarepresents a first lane of the multi-lane road and the second road datarepresents a second lane of the multi-lane road.
 27. The navigationapparatus according to claim 26, wherein the second lane is adjacent toan exit off of the road, and wherein the first lane is not adjacent tothe exit off of the road.
 28. The navigation apparatus according toclaim 26, wherein the first lane is an interior lane of the road, andwherein the second lane is an exterior lane of the road.